Dairy Channel: A twist on feeding dairy cows

Michael F. Hutjens’ presentation at the March 18 Northeast Ohio Dairy Conference introduced me to a different concept in feeding dairy cows.

Hutjens is professor of animal science at the University of Illinois. He is well known as a researcher and educator on the subject of dairy feeding.

I think his approach makes sense and is worthy of further discussion.

Feed efficiency. The concept is to change our thinking from maximizing dry matter intake to optimizing dry matter intake. Hutjens claims the way to do this is to look at dairy efficiency or feed efficiency.

Feed efficiency has been a commonly used benchmark for profitability in beef, swine and poultry feeding for many years.

Feeders of these species know that obtaining maximum feed efficiency, (expressed as pound feed fed per pound weight gained) is important to minimizing both operating and overhead costs.

But until now, dairy researchers and nutritionists have mostly tried to maximize dry matter intake under the assumption this would also maximize returns.

Dairy efficiency or feed efficiency is defined as pounds of milk produced per pound of dry matter consumed.

“With changing (mostly lower!) milk prices, one way to maintain profitability without sacrificing milk production is to enhance feed efficiency,” said Hutjens.

Look at example. The adjacent chart shows an example of how improving feed efficiency affects profitability.

Herd A produced 80 pounds of milk on 57 pounds of dry matter for a feed efficiency of 1.40. Herd B produced the same amount of milk, but the cows consume only 50 pounds dry matter for a feed efficiency of 1.60.

If feed costs were 7 cents per pound of dry matter, Herd B has lower feed costs by 49 cents per cow per day. Furthermore, Herd B, which has lower feed intake and higher feed efficiency, will have lower nutrient excretion rates in manure.

Digestibility factor. High demand for nutrients in high-producing cows lead managers to the reasoning that dry matter intake must be maximized.

The theory was that the more dry matter a cow eats, the more she will milk. Thus, for Holstein cows, each additional pound consumed could result in two more pounds of milk produced.

The problem with this theory is that dry matter digestibility is not constant, it actually declines as dry matter intake increases.

Another problem is that cows do not always use the extra dry matter consumed for milk production, sometimes they use it for growth or weight gain, especially in late lactation and during pregnancy.

Efficiency varies. According to Hutjens, feed efficiency values can vary from 1.1 to 1.8. He said high-producing herds fed a one group total mixed ration will have feed efficiency ranging from 1.4 to 1.6. Early lactation mature cows may have feed efficiency as high as 1.8.

Cows that are losing weight will have higher feed efficiency because some of the nutrients going into the milk come from body condition rather than feed. Pregnancy reduces feed efficiency.

Hutjens’ list. The following is Hutjens’ list of factors influencing feed efficiency values.

* Reducing days in milk should lead to higher feed efficiency. Days in milk (DIM) is huge!

* Older cows will have higher feed efficiency because growth has stopped.

* Pregnancy reduces feed efficiency.

* Cows gaining body weight have lower feed efficiency.

* Highly digestible forages improve feed efficiency.

* Stimulating rumen fermentation while stabilizing the rumen environment will improve feed efficiency.

* Rumen acidosis will reduce feed efficiency.

* Excessive heat and cold reduce feed efficiency values because more nutrients are required for maintenance.

* Feed additives such as rumen buffers, yeast cultures and fermentation/digestion aids and silage inoculants can improve feed efficiency by improving digestion or nutrient availability.

* Using BST may improve feed efficiency.

Fine tuning efficiency. Use energy corrected milk when figuring feed efficiency. Use this formula to figure fat corrected milk:

3.5 percent FCM = (0.4324 X lb of milk) + (16.216 X lb of fat).

Or, you can simply add one pound of milk for each one-10th percentage point above 3.5 percent fat and subtract one pound for each point below 3.5 percent.

So, if the herd averages 70 lb of 3.9 percent milk, the estimated lb of 3.5 percent fat corrected milk would be 74 pounds.

Count what’s left. Dry matter intake must be corrected for feed refusal. Weigh it back and deduct it.

If you feed a ton of feed to 40 cows daily, but there is still 100 pounds left in the bunk at the next feeding, the actual dry matter intake is 2,000 lb/40 cows = 50 lb/cow MINUS 2.5 lb per cow refusal = 47.5 lb DMI.

Other pointers. Additional pointers for managing feed efficiency:

Minimize sorting of TMR. Feed more often, push feed up more frequently, and reduce long forage particle size.

Keep ration dry matter in the range of 45 percent to 50 percent. Below 40 percent, add water to the TMR (5-7 lb./cow/day).

Consider wet molasses, 1/2 to 1 lb /cow/day.

Remove feed refusals, weigh them back and feed them to low producers or older growing heifers.

Keep feed refusals at 2 percent to 4 percent. Reformulate rations when refusals exceed 2 lb./cow.

Learn more. For more information, you can visit Hutjens’ Web site: hutjensm@uiuc.edu.

I can help you calculate feed efficiency for your herd. Call me at 330-424-7291 or e-mail me at Oelker.2@osu.edu.

(The author is an agricultural extension agent in Columbiana County. Questions or comments can be sent in care of Farm and Dairy, P.O. Box 38, Salem, OH 44460.)